15995681 has 6 divisors (see below), whose sum is σ = 17320950. Its totient is φ = 14765088.

The previous prime is 15995671. The next prime is 15995713. The reversal of 15995681 is 18659951.

It can be written as a sum of positive squares in 3 ways, for example, as 1677025 + 14318656 = 1295^2 + 3784^2 .

It is not a de Polignac number, because 15995681 - 2¹⁴ = 15979297 is a prime.

It is a super-2 number, since 2×15995681² = 511723621307522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15995611) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 47156 + ... + 47493.

It is an arithmetic number, because the mean of its divisors is an integer number (2886825).

Almost surely, 2^15995681 is an apocalyptic number.

It is an amenable number.

15995681 is a deficient number, since it is larger than the sum of its proper divisors (1325269).

15995681 is an equidigital number, since it uses as much as digits as its factorization.

15995681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94675 (or 94662 counting only the distinct ones).

The product of its digits is 97200, while the sum is 44.

The square root of 15995681 is about 3999.4600885620. The cubic root of 15995681 is about 251.9615346093.

The spelling of 15995681 in words is "fifteen million, nine hundred ninety-five thousand, six hundred eighty-one".